Martin Mkandawire

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Accumulation of arsenic in Lemna gibba L. was investigated in tailing waters of abandoned uranium mine sites, following the hypothesis that arsenic poses contamination risks in post uranium mining in Saxony, Germany. Consequently, macrophytes growing in mine tailing waters accumulate high amounts of arsenic, which might be advantageous for biomonitoring(More)
The toxicity of arsenic (As) species to Lemna gibba L. and the influence of PO(4) (3-) on As bioavailability and uptake were tested in batch culture. L. gibba were exposed to six test concentrations of NaHAsO(4). 7H(2)O and NaAsO(3), with 0, 0.0136, 13.6, and 40 mg L(-1) KH(2)PO(4). In batch culture As toxicity to L. gibba did not relate linearly to As(More)
The potential of Lemna gibba L. to clean uranium and arsenic contamination from mine surface waters was investigated in wetlands of two former uranium mines in eastern Germany and in laboratory hydroponic culture. Water and plants were sampled and L gibba growth and yield were monitored in tailing ponds from the field study sites. Contaminant accumulation,(More)
Organic sediments are known to be a significant sink of inorganic elements in polluted freshwater ecosystems. Hence, we investigated the role of invertebrate shredders (the freshwater shrimp Gammarus pulex L.) in metal and arsenic enrichment into organic partitions of sediments in a wetland stream at former uranium mining site. Metal and metalloid content(More)
The focus of this article is to combine two main areas of research activities in freshwater ecosystems: the effect of inorganic pollutants on freshwater ecosystems and litter decomposition as a fundamental ecological process in streams. The decomposition of plant litter in aquatic systems as a main energy source in running water ecosystems proceeds in three(More)
Biofilters with long lifetime and high storage stability are very important for bioremediation processes to ensure the readiness at the occurrence of sudden contaminations. By using the freeze-gelation technique, living cells can be immobilized within a mechanically and chemically stable ceramic-like matrix. Due to a freeze-drying step, the embedded(More)
Growth behaviour of Lemna gibba L. at different phosphorus supply, and arsenic or uranium exposure levels was investigated in batch culture. Total frond count, total frond area, and dry biomass were used to observe growth at four phosphate, arsenic, and uranium concentrations. L. gibba dry biomass had a linear relationship with the total frond area (r=0.96(More)
To narrow the differences between the results obtained from radionuclides and heavy metal ecotoxicity investigations in the laboratory and in the abandoned uranium mines, a few standardised plant bioassay procedures were selected from the literature for testing with Lemna gibba L. The bioassay procedures were tested in situ and ex situ. The laboratory(More)
The influence of phosphate on the toxicity of uranium to Lemna gibba G3 was tested in semicontinuous culture with synthetic mine water developed as an analogue of surface water of two abandoned uranium mining and ore processing sites in Saxony, Germany. Six concentrations of uranium were investigated under five different supply regimes of PO(4) (3-) at(More)
We investigated responses of Lemna gibba L. to exposure to UO(2)(2+) and AsO(4)(3-) under variable PO(4)(3-) concentration. Total plant phosphorus (P(tot)) in L. gibba and accumulation of dissolved organic carbon (DOC) in the media were quantified and tested for correlation with plant yield and initial concentrations of PO(4)(3-), UO(2)(2+) and AsO(4)(3-).(More)